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Effects of 2,4-D, glyphosate and paraquat on growth, photosynthesis and chlorophyll-a synthesis of Scenedesmus quadricauda Berb 614

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CHEMOSPHERE 2000年第1-2期41卷 177-182页

作者： Wong, PK Chinese Univ Hong Kong Dept Biol Hong Kong Hong Kong Peoples R China

The effects of 2,4-D, glyphosate and paraquat on growth, photosynthesis and chlorophyll-a synthesis by a freshwater green alga, Scenedesmus quadricauda Berb 614, were determined. These herbicides are the most often used in Hong Kong. Within the concentration range 0.02-200 mg/l, paraquat was more toxic than glyphosate and 2,4-D to the growth, photosynthesis and chlorophyll-a synthesis. The presence of 0.02, 0.2 or 2 mg/l of 2,4-D was not toxic to the alga. Algal growth, photosynthesis and chlorophyll-a synthesis were stimulated by the presence of low concentrations (0.02 or 0.2 and 0.02 mg/l, respectively) of 2,4-D and glyphosate. The presence of 0.02 or 0.2 mg/l of paraquat, 2 mg/l of glyphosate or 20 mg/l of 2,4-D was significantly inhibitory to the three test parameters, whereas the presence of 2 or more mg/l of paraquat, 20 or more mg/l of glyphosate or 200 mg/l of 2,4-D completely inhibited algal growth, photosynthesis and chlorophyll-a synthesis. The use of the alga as a bio-indicator of herbicide contamination in freshwater environment was discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： 2 4-二氯苯氧乙酸/副作用叶绿素/生物合成绿藻门/药物作用绿藻门/生理学剂量效应关系药物甘氨酸/副作用甘氨酸/类似物和衍生物除莠剂/副作用百草枯/副作用光合作用/药物作用水污染物化学性/副作用

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Tris(3-mercaptopropyl)-N-glycylaminomethane as a new linker to bridge antibody with metal particles for biological cell separations

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BIOCONJUGATE CHEMISTRY 2000年第4期11卷 549-556页

作者： Siiman, O Burshteyn, A Maples, JA Whitesell, JK Beckman Coulter Inc Adv Technol Miami FL 33196 USA Beckman Coulter Inc Reagents Applicat & Dev Miami FL 33196 USA N Carolina State Univ Dept Chem Raleigh NC 27695 USA

Conjugates of nickel beads with CD8 and anti-red blood cell KC16 antibody were prepared by using the aminotrithiolate "spider" ligand, tris(3-mercaptopropyl)-N-glycylaminomethane, in its new function as a linker between the surface of nickel beads and antibody via activation of spider ligand attached to nickel beads with the common, heterobifunctional cross-linker, sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (sulfo-SMCC). Raw nickel beads were cleaned by either mild sonication in a bath or by stronger probe sonication to remove surface nickel oxide layers, before attachment of the spider ligand. Scanning electron micrographs of the nickel beads before and after probe sonication showed a marked change from a corrugated to a smooth bead surface. Analyses of the supernatants of conjugation mixtures for antibody gave surface densities of 2.5-5.2 mg/m(2) for CD8 and 0.6-12 mg/m(2) for KC16 antibody runs. The antibody-spider-nickel bead conjugates were used in magnetic bead depletions of targeted CD8+ lymphocytes or red blood cells (rbcs) in whole blood of normal donors. For CD8 cell depletions, the undepleted controls and supernatants of depleted samples were analyzed for CD8/CD4 cell populations by now cytometry with appropriate fluorescent antibody markers. Enumeration of red blood cells, white blood cells (wbcs), and platelets (plts) in undepleted controls and supernatants of depleted samples were carried out on appropriate hematology counters. Whale blood titer results with various lots of either CD8-spider-nickel or KC16-spider-nickel bead conjugates showed varying degrees of depletion ability as indicated by bead-to-cell ratios of 2-32 for CD8 beads and by rbc-to-bead ratios of 1.2-10 for KC16 beads. Moreover, varying degrees of specificity of CD8 beads for CD8+ cells over CD4+ cells and of KC16 beads for rbcs over white blood cells and platelets were observed from the normalized nontargeted cell population figures in undepleted controls versus

关键词：抗体/化学抗体/免疫学抗原 CD8/免疫学 CD8阳性T淋巴细胞/免疫学甘氨酸/类似物和衍生物甘氨酸/化学淋巴细胞去除术显微镜检查电子扫描镍/化学巯基化合物/化学人类

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Determination of glyphosate residues in plants by precolumn derivatization and coupled-column liquid chromatography with fluorescence detection

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JOURNAL OF AOAC INTERNATIONAL 2000年第3期83卷 728-734页

作者： Hernández, F Hidalgo, C Sancho, JV Univ Jaume 1 Expt Sci Dept Castellon de La Plana 12080 Spain

A rapid method was developed for the trace-revel determination of glyphosate in olives. After extraction of the glyphosate with water-dichloromethane and simultaneous removal of the olive oil, an aliquot of the aqueous extract is derivatized with 9-fluoroenylmethyl chloroformate (9-fluorenylmethoxycarbonyl chloride;FMOC-Cl) to produce a highly fluorescent derivative. A 2 mt aliquot of this extract is injected directly into a coupled-column liquid chromatography system with fluorimetric detection (LC/LC-FD). The procedure was validated by recovery experiments at 3 spiking levels;recoveries ranged from 80 to 97% with relative standard deviations of 3-6%. The limits of detection and quantitation were estimated to be 0.01 and 0.05 mg/kg, respectively. The method was also applied to other plant materials, i.e., tomato plants, strawberry plants, and pear trees (branches, leaves, and fruits) suspected to be contaminated by glyphosate. In all these cases, the extraction was performed in aqueous media. The derivatization reaction was modified by increasing the FMOC-Cl concentration, to ensure a quantitative reaction between analyte and reagent in the presence of high levels of coextractives, which also react with FMOC-Cl, The final determination was by LC/LC-FD, yielding a rapid, selective, and sensitive method for the determination of glyphosate residues in these samples. The method was tested with real-world samples after application of glyphosate to the surrounding area of crops.

关键词：色谱法液相/方法甘氨酸/类似物和衍生物甘氨酸/分析除莠剂/分析植物提取物/化学光谱法荧光

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One-step production of D-p-hydroxyphenylglycine by recombinant Escherichia coli strains

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BIOTECHNOLOGY PROGRESS 1999年第6期15卷 1039-1045页

作者： Chao, YP Fu, HY Lo, TE Chen, PT Wang, JJ Feng Chia Univ Dept Chem Engn Taichung 40724 Taiwan Acad Sinica Inst Bot Taipei Taiwan Tungfang Jr Coll Technol & Commerce Dept Food Engn Kaohsiung Taiwan

The gene encoding D-hydantoinase from Agrobacterium radiobacter NRRL B11291 was successfully cloned by use of polymerase chain reaction. A positive clone was scored, and its nucleotide sequence was further analyzed. The analysis by deleting various lengths of nucleotides from the amino terminus of the open reading frame revealed the putative regions for promoter and RBS site. By highly expressing both D-hydantoinase and carbamoylase, recombinant Escherichia coli strains were able to convert DL-hydroxyphenyl hydantoin (DL-HPH) to D-p-hydroxyphenylglycine (D-HPG) with a conversion yield of 97%, accounting for productivity 5 times higher than that obtained by A. radiobacter NRRL B11291. Immobilizing the recombinant cells with kappa-carrageenan could also achieve a conversion of 93%, while A. radiobacter NRRL B11291 attained 20% within the same period of reaction time. These results illustrate the feasibility in employing recombinant E, coli to accomplish one-step conversion of DL-HPH to D-HPG. In the process of improving D-HPG production, D-hydantoinase activity was increased 2.57-fold but carbamoylase activity remained constant, which resulted in only a 30% increase in the reaction rate. It suggests that carbamoylase is the step setting the pace of the reaction. Since the reaction substrate is highly insoluble, achieving sufficient agitation appears to be an important issue in this heterogeneous system. This view is further supported by the study on repeated use of cells, which shows that to reach a conversion of more than 90% free cells can be recycled six times, whereas immobilized cells can be used only twice. In conclusion, the poor reusability of immobilized cells is due to the fouling on the gel surface.

关键词：酰胺基水解酶类/遗传学酰胺基水解酶类/代谢碱基序列生物技术/方法细胞固定化克隆分子/方法大肠杆菌/代谢基因细菌甘氨酸/类似物和衍生物甘氨酸/生物合成甘氨酸/化学合成分子序列数据重组蛋白质类/代谢根瘤菌属/酶学根瘤菌属/遗传学

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Ion exchange chromatography of aluminum using 3-carboxy-2-naphthylamine-N,N-diacetic acid as a fluorescent post-column chelating reagent

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BIOMEDICAL CHROMATOGRAPHY 1999年第1期13卷 70-74页

作者： Miyahara, T Kitamura, H Narita, K Toyo'oka, T Univ Shizuoka Dept Pharmaceut Sci Shizuoka 4228526 Japan

Ion exchange chromatography of aluminum ion using 3-carboxy-2-naphthylamine-N,N-diacetic acid (CNDA) as a fluorescent post-column chelating reagent was studied. The solution containing ammonium chloride and hydrochloric acid was used for the eluent, and acetate buffer solution containing CNDA was used for the post column chelating reagent. The peak of aluminum was separated from that of calcium, magnesium and zinc, and the chromatogram was not affected by copper(II) and iron(III). The calibration curve gave linear plots with a range of 0.0027-0.54 ppm aluminum, the regression coefficient of correlation (r(2)) was 1.000, and the detection limit (S/N = 3) was 0.3 ppb, indicating that the method could determine aluminum with high sensitivity. It was demonstrated that CNDA is a useful metallofluorescent reagent for aluminum. This method has been successfully applied to the determination of aluminum in some tea drinks. Copyright (C) 1999 John Wiley & Sons, Ltd.

关键词：铝/分析阴离子阳离子螯合剂/化学色谱法离子交换/方法荧光染料/化学甘氨酸/类似物和衍生物甘氨酸/化学萘类/化学光谱法荧光茶/化学

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Glycinium oxalate

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ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2001年第1期57卷 115-116页

作者： Nandhini, MS Krishnakumar, RV Natarajan, S Madurai Kamaraj Univ Dept Phys Madurai 625021 Tamil Nadu India Thiagarajar Coll Dept Phys Madurai 625009 Tamil Nadu India

In the title compound, C2H6NO2+.C2HO4-, the glycine molecule exists in the cationic form and the oxalic acid molecule in the mono-ionized state. The molecules aggregate into alternate columns of glycinium and semi-oxa... 详细信息

关键词：结晶学 X线甘氨酸/类似物和衍生物甘氨酸/化学氢键合模型分子分子构象草酸盐类/化学

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Analysis of polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis alongside in vitro-generated reference peptides

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ANALYTICAL BIOCHEMISTRY 2003年第2期319卷 327-331页

作者： Lemberg, MK Martoglio, B ETH Honggerberg Swiss Fed Inst Technol Inst Biochem CH-8093 Zurich Switzerland

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Production of D-p-hydroxyphenylglycine by N-carbamoyl-D-amino acid amidohydrolase-overproducing Escherichia coli strains

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BIOTECHNOLOGY PROGRESS 1999年第4期15卷 603-607页

作者： Chao, YP Juang, TY Chern, JT Lee, CK Feng Chia Univ Dept Chem Engn Taichung 40724 Taiwan Natl Taiwan Univ Dept Chem Engn Taipei 106 Taiwan

The N-carbamoyl-D-amino acid amidohydrolase (D-carbamoylase) gene from Agrobacterium radiobacter NRRL B11291 has been successfully cloned and expressed in Escherichia coli. Subcloning of the D-carbamoylase gene into different types of vectors and backgrounds of E. coli strains showed that the optimal expression level of D-carbamoylase was achieved in a ColE1-derived plasmid with a 150-fold increase in specific enzyme activity compared to that in a pSC101-derived plasmid. In addition, the recombinant plasmids were very stable in the E. coli strain ATCC11303 but not in JCL1258 tested here. Employing the recombinant E, coli strain DH5 alpha/pAH61 for D-p-hydroxyphenylglycine production showed that the cell was capable of transforming N-carbamoyl-D-hydroxylphenylglycine to D-p-hydroxyphenylglycine with a molar conversion yield of 100% and a production rate of 1.9 g/(L h). In comparison with A. radiobacter NRRL B11291, this productivity approximates a 55-fold increase in D-hydroxyphenylglycine production. This result suggests the potential application of recombinant E. coli strains for the transformation reaction.

关键词：酰胺基水解酶类/生物合成酰胺基水解酶类/遗传学生物反应器克隆分子大肠杆菌/酶学大肠杆菌/遗传学大肠杆菌/代谢甘氨酸/类似物和衍生物甘氨酸/生物合成甘氨酸/代谢质粒/遗传学重组遗传根瘤菌属/酶学根瘤菌属/遗传学

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Adenosine A1 and class II metabotropic glutamate receptors mediate shared presynaptic inhibition of retinotectal transmission

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JOURNAL OF NEUROPHYSIOLOGY 1999年第6期82卷 2947-2955页

作者： Zhang, CY Schmidt, JT SUNY Albany Neurobiol Res Ctr Albany NY 12222 USA SUNY Albany Dept Biol Sci Albany NY 12222 USA

Presynaptic inhibition is one of the major control mechanisms in the CNS. Previously we reported that adenosine Al receptors mediate presynaptic inhibition at the retinotectal synapse of goldfish. Here we extend these findings to metabotropic glutamate receptors (mGluRs) and report that presynaptic inhibition produced by both Al adenosine receptors and group II mGluRs is due to Gi protein coupling to inhibition of N-type calcium channels in the retinal ganglion cells. Adenosine (100 mu M) and an Al (but not A2) receptor agonist reduced calcium current (ICa2+) by 16-19% in cultured retinal ganglion cells, consistent with their inhibition of retinotectal synaptic transmission (-30% amplitude of field potentials). The general metabotropic glutamate receptor (mGluR) agonist 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD, 50 mu M) and the selective group II mGluR receptor agonist (2S,2'R,3'R)-2-(2',3'-dicarboxy-cyclopropyl)glycine (DCG-IV, 300 nM) inhibited both synaptic transmission and ICa2+ whereas the group III mGluR agonist L-2-amino-4-phosphono-butyrate (L-AP4) inhibited neither synaptic transmission nor ICa2+. When the N-type calcium channels were blocked with omega-conotoxin GVIA, both adenosine and DCG-IV had much smaller percentage effects on the residual 20% of ICa2+ suggesting effects mainly on the N-type calcium channels. The inhibitory effects of A1 adenosine receptors and mGluRs were both blocked by pertussis toxin, indicating that they are mediated by either Gi or G(o). They were also inhibited by activation of protein kinase C (PKC), which is known to phosphorylate and inhibit G(i). Finally, when applied sequentially, inhibition by adenosine and DCG-IV were not additive but occluded each other. Together these results suggest that adenosine A1 receptors and group LT mGluRs mediate presynaptic inhibition of retinotectal synaptic transmission by sharing a pertussis toxin (PTX)-sensitive, PKC-regulated G(i) protein coupled to N-type calcium chan

关键词：腺苷/药理学钙通道/药物作用钙通道/生理学细胞培养的环丙烷类/拮抗剂和抑制剂酶激活/生理学 GTP结合蛋白质α亚单位 Gi-Go/生理学甘氨酸/类似物和衍生物甘氨酸/拮抗剂和抑制剂金鱼膜电位/生理学百白咳毒素蛋白激酶C/代谢嘌呤能P1受体激动剂受体亲代谢性谷氨酸盐/拮抗剂和抑制剂受体亲代谢性谷氨酸盐/生理学受体突触前/药物作用受体突触前/生理学受体嘌呤能P1/生理学视网膜/生理学视网膜神经节细胞/生理学上丘/生理学突触/生理学突触传递/药物作用突触传递/生理学毒力因子鲍特菌属/药理学动物

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Polymeric [μ₃-(N-phosphonomethyl)-glycinato]tris(tri-n-butyltin)

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ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2001年第3期57卷 254-256页

作者： Khoo, LE Hazell, A Aarhus Univ Dept Chem DK-8000 Aarhus C Denmark Nanyang Technol Univ Natl Inst Educ Singapore 637616 Singapore

N-(Phosphonomethyl)glycine, glyphosate, reacts with bis(tributyltin) oxide to form a ligand-tin (1:3) complex in which all five O atoms are coordinated to tin. The complex, [Sn-3(C4H9)(9)(C3H5NO5P)], is polymeric, with the glyphosate and two tributyltin groups forming a two-dimensional network and with the third Sn atom alternately above and below the plane of the net. The Sn atoms in the network have a trigonal-bipyramidal coordination, with O atoms in the axial positions and C atoms in the equatorial positions;the pendant tributyltin group is tetrahedrally coordinated to one O atom and to three butyl groups. Sn-O distances vary from 2.030 (3) to 2.408 (3) Angstrom. The Sn-O distances for O atoms trans to carboxylate groups are shorter than those trans to phosphonate groups and d(Sn-O) decreases with increasing d(C/P-O) (Delta (Sn-O) similar or equal to -4.6 Delta (C/P-O)). The amino N atom in the ligand is neither protonated nor involved in coordination to the Sn atoms.

关键词：结晶学 X线甘氨酸/类似物和衍生物甘氨酸/化学合成甘氨酸/化学模型分子分子构象有机锡化合物/化学合成有机锡化合物/化学

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